The design and manufacturing of the suspension systems supporting the cargo holding structure installed on top of the axles employed in the construction of heavy weight ground vehicles poses a difficult problem that has not found any easy solution. Without any exception, the conventional design of all heavy ground vehicles prescribes the suspension system installed between the wheel axles and the carriage frame, which design has two serious faults in that, firstly, new suspension systems such as an air-spring system cannot be employed because of the limited space available intermediate the wheel axles and the carriage frame and, secondly, it has never examined the usefullness of employing more than one suspension system installed in series. The logic is crystal clear that the shock load on the primary suspension systems installed between the axles and the carriage frame can be drastically reduced if the secondary suspension system providing air cushions such as elastic compressed air containers are installed between the carriage frame and the cargo bed in the construction of heavy trucks, rail road flat cars and box cars and between the carriage frames and car body in the construction of tanks and armored vehicles.
The primary object of the present invention is to provide an air-spring suspension comprising a plurality of elastic compressed air containers installed intermediate the carriage frame supported on the wheels or endless tracks and the cargo holding structure supported by the carriage frame.
Another object is to provide an air-spring suspension beam comprising a pair of elongated members separated by a plurality of elastic compressed air containers providing cushioning for relative movements therebetween in the lateral direction.
A further object is to provide the air-spring suspension beam equipped with means for damping the oscillatory movements between the two elongated members constituting the air-spring suspension beam.
Yet another object is to provide a secondary suspension system for the ground vehicles that is installed in a series arrangement with the primary suspension system comprising the mechanical springs and shocks.
Yet a further object is to provide an additional suspension system for the ground vehicles installed in a series arrangement with the conventional suspension system installed on the axles of the vehicles wherein the magnitude of the suspension force is easily adjustable.
These and other objects of the present invention will become clear as the description thereof proceeds.